Unfortunately I think you will find that it's not possible in Coos County, unless you are building a home, then only for 12 months. Below is the ordinace for the city of Coquille, and the county follows pretty closely.
Ordinance 17.36.060 section I
"There is a six-month limitation on residential use of mobile home or recreational vehicle placed outside an approved mobile home park or recreational vehicle park in the city. Up to twelve (12) months residential occupancy may be allowed where a mobile home or recreational vehicle is placed on a property undergoing development, subject to review and approval by the planning official and compliance with other requirements of the development code."
Other zoning, such as CREMP (Coquille River property) has 60 days maximum.